Eleminated debugging print of numerator,denominator in utils.py, which debugged some errors with divide by zero in rational type conversion and attempts to convert non-fractions to Rational type (integers). Rather than throwing an exception, conversion to Rational type now assumes a 1 in the denominator whenever it's zero or not-given

Added __repr__ method in utils.Rational class so that printing arrays of Rational objects like print([Rational(1,2),Rational(3,4)]) display the object values rather than its trace (name, rank, and serial number :).